The Dwarves who dwelt in the halls of Erebor, beneath the Lonely Mountain. The Dwarve may first colonized the mountain as early as the Second Age, but it was first densley popultaed during Third Age after the awakening of the Balrog and the flight of Durin's folk from Khazad-dum. Thrain I, established a kingdom then-after. His son Thorin I later became King Under the Mountain and after seeing the wealth of the Dwarves of the Grey Mountains he abandoned Erebor. Until, the Cold-Drakes, invaded the Grey Mountains and drove the Dwarves out. Thror the son of Thorin I, took some of his people to Erebor and refounded the kingdom. The Dwarves were properous and made great wealth for themselves until, they were dispossessed of their immense wealth by Smaug the Dragon, who sacked their kingdom, but they famously reclaimed their inheritance many years later under the leadership of Thorin Oakenshield.